Yes, quite interesting. I would guess the machine suffered from a blade failure. I have been involved with evaluating various blade manufacturers over the last 2 years and what is most interesting is that the quality of blade manufacture has diminished somewhat by companies hiring inexperienced workers. Due diligence of various wind turbine OEM's revealed each blade is manufactured manually with no two blades identical in quality.
Now that's something that I haven't seen. How are the blades constructed and what QA testing methods are applied to the blade manufacturing process?
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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
I saw a follow-up article that indicated the turbine went into an overspeed condition caused by faulty wiring.
Re; blade manufacture high level overview;
the typical wind turbine blade design is similar to an aircraft wing. You have a center box beam or spar that supports the balde itself and is constructed of wood laminate with fiberglass or carbon fiber with fiberglass followed by pressure side and suction side skins that are all fiberglass.
The entire blade is manufactured by gluing the spar or box beam to the inner surface of the pressure side and suction side airfoils (skins). The QA problems I have seen are dry spots (lack of resin impregnation) and wrinkles followed by lack of consistent application of adhesive.
That's a pretty high gust to maximum ratio. If overspeed was the cause, I'd suspect the anemometer either was positioned too low, or just wasn't looking when the true maximum gust went by.
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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
The company's latest press release hints that something else happened. They may just be covering their a**es, but the release reports a loss of power before the command to shut down.
One idea that comes to mind is that if there was a break in the transmission line that connects them to the rest of the grid, then no synchronization frequency would be available to govern their speed. Without the grid synchronizing and loading them, then some certainly could get away. The safety machanism that feathers the blades if this happens worked on 63 out of 65 in the wind park. There was a fault in two of them and it proved fatal in one, though the second was also damaged.
For the time being Noble and GE are still working together on this, but stay tuned for the fireworks if they start pointing fingers!
